Gas-purifier.



No. 872,576. PATENTED DEC. 3, 1907. D. F. NISBET.

GAS 'PURIFIBR.

APPLICATION FILED JULY a. 1907.

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A'r'I- RNKY I No. 872,576. PATENTED DEC. s, 1907. 1). P. NISBET.

v GAS PURIFIER. ABPLIOATION FILED JULY8.'1907.

' 4 SHEETS-SHEET 2.

ATTORNEY DAVID F. NISBET, OF WILKINSBURG, PENNSYLVANIA.

GAS-PURIFIER.

Specification of Letters Patent.

Patented Dec. 3, 1907.

Application filed July 3. 1907. Serial No. 382587 T 0 all whom it mayconcern:

Be it known that I, DAVID F. NISBET, a citizen of the United States,residing at Wilkinsburg, in the county of Allegheny and State ofPennsylvania, have invented or dis covered new and useful Improvementsin Gas-Purifiers, of which the following is a specification.

This invention relates to apparatus used in connection with blastfurnaces, gas producers, etc. and intended for the preliminary cleansingof the gas by removing all the larger impurities in form of dust and alarge percentage of the finer particles, and purifying the gas to adegree that will permit of its being burned in blast heating stoves orunder boilers without clogging the flues of the stoves or tubes of theboilers, thus detracting from their efliciency; or my invention may beused as preliminary to further cleansing of gas for use in gas engines.

In the accompanying drawings which form a part of thisspecification,Figure 1 is a sectional elevation of one form of my inven tion showing adust catcher, a single-pass gaswasher and a singleass reheater; Fig. 2,a cross section on the ine 22,' Fig. 1, of the washing pass; Fig. 3, asectional elevation of a second form of my invention showing a dustcatcher, a two-pass gas-washer and a single-pass reheater; Fig. 4, across section on line 44, Fig. 3; Fig. 5, a sectional elevation of athird form of my invention showing a dust catcher, a two-passgas-washer, and a two-pass reheater; Fig. 6, a side elevation of thesame; and Fig. 7, a section on the line 77, Fig. 5.

Referring to Figs. 1 and 2 of the drawings,

, 1 is a conduit leading unpurified gases from a blast-furnace or othersource into the large chamber 2 serving as a dry dust-catching element.This chamber is larger than the cross-section of the conduit in orderthat the gases may expand therein and deposit a large portion of thedust carried along with them. Preferably, the sides of the chamber 2converge downwardly, the upper end being closed and the lower end being0 en directly over the water tank 3. The si e walls and the top of thechamber 2 are double, 4 re resenting the washing and cooling passes w'ch are in the side-walls, and 5 representing the gas-reheating passesin the top-wall. The

passes 4 have their lower ends open and at the level of the bottom ofthe chamber 2 and their upper ends in communication with the passes 5which are inclined upwardly and lead into the off-take pass or conduit6, leading to the stoves and boilers or to other apparatus for furtherpurification.

The tank 3 has sloping sides which meet under the center of the chamber2, the tank being provided with skimmers 7, (see Figs. 3 and 5) whichdrain ofl through the pipes 8 and tra s 9 the floating accumulationsfrom the sur 'ace of the water in the tank. These skimmers are merelyfunnel-like boxes located at the water level with connection to the saidwaste pipes and traps. The lower ends of the traps 9 are closed by thebells 9 held in place by the weighted levers 9 which may be operated bywires, one, as 9 being shown on Fig. 3. These wires or cords run overidle pulleys, as 9*, so that the outer end of each lever may be raisedby a downward pull on the end of a wire. The tank 3 is provided alongits bottom with a number of sludge gates 10, preferably provided withbells like those for the traps 9, the bells or gates being held in placeby weighted levers, and operated by means of cords and pulleys likethose used with the bells 9 In the chamber 2 are the deflecting platesor dust guides 11, which are surfaces inclined downwardly toward eachother but with their inner ends not touching, so that the dust whichstrikes the guides will slide toward the center line of the chamber 2and fall into the water centrally between the sides of the chamber,whereby the engagement of the particles of dust with the water will bemore positively secured than if the gases took the shortest paths fromthe inlet conduit 1 and turned a sharp angle around the lower ends ofthe inner walls of the chamber.

The upper outer wall is provided with the manholes 12 opposite thepasses 4 for the purpose of giving access to the passes 4 and 5 in casethey should need repairing or cleaning. The upper ends of the passes 4are provided with the perforated water pipes 18 which discharge streamsof Water down the passes 4 in contact with the inner surfaces of theouter side walls. These outer walls are continued vertically downwardfrom their lower ends by the dividing flanges 14, which extend below thesurface of the water in the tank. The sides of the tank and the flangeswill be so proportioned that the pressure of the gases on the waterbetween the flanges will be counterbalanced by the columns of water atthe outer sides of the flanges without a discharge of water over thesides of the tank.

The hot, unpurifled gases, coming from a primary dry dust catcher ordirect from the blast furnace, contains an amount of dust, varying from2 to 5 grains per cubic foot and the quantity of gas per ton of ironproduced will average 124,000 cu. ft. It is obvious that, as thepresence of this dust is wholly detrimental to the use of the gas, it isdesirable to eliminate it as far as possible. The gas, which has atemperature varying from 300 to 500 F., also contains a large amount ofwater in the form of vapor, which is also detrimental to its use; but asthe use to which thegas is put, 'i. 6., burning it in blast-heatingstoves and under boilers, renders it desirable that the heat contained.in the gas should be retained, while the water vapor is eliminated, andas the only practicable way by which the vapor can be eliminated economically, is by cooling the gas to a point where the vapor will becondensed, it follows that the gas must be first cooled and purified.and then reheated. To do this I have devised the apparatus abovedescribed, the operation of which is as follows :The gas is conveyedthrough the conduit 1 to the large chamber 2 where the velocity of thegas, by reason of the greatly increased area, is much reduced,permitting the heavier portions of the dust carried in suspension by thegas to fall by the action of gravity to the surface of the water in thetank 3, the deflecting plates 11 assisting in carrying the dust to thecenter of the current of gases to prevent, as far as possible, theshort-circuiting of the dust and carrying it into the Washing andcooling passes. The gases, deprived of the heavier dust and carried asshown by the arrows, are divided at the bottom of the (lust catcherelement and impinging on the surface of the water contained in the tank3 lose a portion of their dust. The gases then enter the washing andcooling passes 4, passing upward through them against the streams orsheets of water which issue from the perforated pipes 13 and descend onthe bottom of the passes. This passing of the gases in a directioncontrary to the flow of the water, necessarily causes the gasesimpinging on the water to take the direction of the flow of water, thusgiving the gas a rolling motion throughout these passes and bringingevery portion of the gases into intimate contact with the water, whichrapidly absorbs a large percentage of the dust remaining in the gas, andalso partially cools the same. The gases are reheated as they go alongthe passes 5. The impurities on the surface of the water may be drainedoff from time to time by lowering the bells 9 and the impurities in thebottom of the trough maybe discharged by lowering the gates or bells 10in an obvious manner.

In Fig. 3, there are no deflecting plates, but there are extra washingand cooling passes 4 lying between the inner walls of the passes 4 andthe additional walls 15, whose upper ends do not reach the top of thechamber, and whose lower ends extend down to the level of the lower edgeof the flanges 14. A trough 16 is located at the lower end of the middlewall of the passes 4 to catch the wash-water from the passes 4 andconvey it to the tank 3 through the pipes 17, thus preventing the gaseswhile flowing from the passes 4 to the passes 4 from flowing throughsheets of water and absorbing moisture therefrom. Skimmers 7 areprovided in the space between the walls 15 and in the spaces betweeneach flange 14 and the adjacent wall 15, the pipes 8 leading to a commonpipe 8 having the bell 9. The gases enter the chamber 2 where theydeposit a portion of their dust in the water between the walls 15. Fromthe chamber 2 the gases flow over the top of the walls 15 and down thepasses 4, in which they come in contact with streams of water flowingfrom the pipes 13 down the middle walls. The gases then flow beneath thetroughs 16 and impinge on the surface of the water between the flanges14 and the walls 15, where more dust istaken from the gases. They thenpass up the passes 4, and along the reheating passes 5, and out throughthe conduit 6, as in Fig. 1.

Referring now to Figs. 5 and 6, the parts are as in Figs. 1 and 2 exceptas follows: From each pass 4 the gases flow over the top of the innerwall thereof and down the pass 4 which is provided with the pipe 13supplying water to the inclined floor wall thereof. The gases pass fromthe bottom of each pass 4 beneath the inner wall thereof and up thereheating pass 4 the lower ends of the inner walls of the passes 4 and 4being connected by the floor 18, so that the gases cannot touch thewater while passing from the passes 4 to the passes 4. The top of thepasses 4 open into the reheating passes 5. Pipes 19 drain the water fromthe floor 18 into the pan 3. The gases in the conduit 1 enter thechamber 2 and descend into contact with the water in the tank 3, whencethey divide and flow up the washing and cooling passes 4, curling asthey go, as in Fig. 1. They then flow down the washing and coolingpasses 4 thence up the reheating passes 4 and thence along the reheatingpasses 5 into the off-take conduit 6.

I claim 1. In an apparatus of the class described, a gas receivingchamber having an open bottom, a water-tank below the chamber, a gas-Washing pass in one of the walls of said cham* ber, means for supplyingwater to said pass, and a gas reheating pass contiguous to said pass.

chamber and connected to the gas-washing 2. In an apparatus of the classdescribed, a gas receiving chamber, a Washing pass and a gas receivingchamber, a tank below the a reheating pass in one side Wall, and aresame, Washing passes in the sides of the heating pass in the roof,said passes and chamber, and reheating passes in the roof chamber beingconnected in series. 15 5 thereof. Signed at Pittsburg, Pa, this 3rd dayof 3. In an apparatus of the class described, July, A. D. 1907. a gasreceiving chamber, a pair of series Wash- AVID F NISBET ing passes inone Wall, and reheating passes in the roof in series with the chamberand Witnesses: 10 the respective washing passes. ELVA WANIEK,

4. In an apparatus of the class described, F. N. BARBER.

